Question

i need to create a python function that reads and lists groceries from a file called “food.txt” such that when ever a new line in the textfile is found, a new list grouping within the general list is created.

food.txt:

milk
cheese
bread

steak
chicken
potatoes

^ each word should be on its own line with a single new line between the groups

output: [[‘milk’,’cheese’,’bread’],[‘steak’,’chicken’,’potatoes’]]

so far i have:

   def build_grocery_list(file_name):
        outer_list=[]
        inner_list=[]

        food_list=open(file_name,"r")
        for line in food_list:
            line.strip('\n') # no white spaces in the list

Answer 1

Try this (here is a gist):

list_of_lists=[]
category=0
list_of_lists.append([])

f = open(file_name,'r')

for line in f.readlines():
    item = line.strip('\n') # no white spaces in the list
    if len(item) > 0:
         #add to current category
         list_of_lists[category].append(item)
    else:
         #add new category
         list_of_lists.append([])
         category = category + 1
f.close()